Understand the purpose and functionality of utility software (file repair,…

The idea

Utility software keeps a computer system healthy and usable. File repair scans a damaged file's structure and rebuilds what it can, so a corrupted document may open again. Backup copies files or whole drives to another location, either fully or incrementally, so data can be restored after loss. Data compression reduces file size by removing redundancy, saving storage and speeding up transfer; it can be lossless or lossy. Disk defragmentation rearranges fragmented files on a magnetic hard disk so blocks are contiguous, improving read speed. Anti-malware detects, quarantines and removes viruses and other malicious programs, and updates its definitions to recognise new threats. Each tool has a distinct purpose, and choosing the right one depends on the problem: a slow hard disk suggests defragmentation, whereas a suspected virus suggests anti-malware.

What earns the marks

• File repair: identifies and rebuilds corrupted file structures so the file can be opened again.
• Backup: creates a copy of files or a drive, full or incremental, so data can be restored after loss or damage.
• Data compression: reduces file size by removing redundancy, saving storage space and reducing transfer time; may be lossless or lossy.
• Disk defragmentation: rearranges fragmented files on a magnetic hard disk into contiguous blocks to improve read speed.
• Anti-malware: detects, quarantines and removes malicious software, and updates definitions to recognise new threats.
• Selecting the appropriate utility for a given problem, such as defragmentation for a slow hard disk or anti-malware for a suspected infection.

Common mistakes and how to put them right

• Confusing backup with compression.

  Put it right: Backup copies data for restoration, whereas compression reduces file size; a compressed file is not a backup unless it is stored separately.

• Thinking defragmentation applies to solid-state drives.

  Put it right: It is intended for magnetic hard disks, and running it on an SSD causes unnecessary wear without speed benefit.

• Believing anti-malware only removes viruses.

  Put it right: It also detects and quarantines other malware such as worms, trojans and spyware, and needs updated definitions.

• Assuming file repair can recover any file.

  Put it right: It rebuilds damaged structures but cannot restore data that has been overwritten or physically destroyed.

Exam tips

• Match each utility to a specific problem in the question, for example a slow hard disk to defragmentation and a suspected infection to anti-malware.
• Use the term 'redundancy' when explaining compression, and state whether the method is lossless or lossy if the question asks.
• For backup, mention what is copied and where it is stored, and note that a backup must be separate from the original to be useful.